Store the TinyPilot bundle as a build artifact in CI (#1216)

Now that we're building the bundle on non-master branches, it's helpful
to store it as a CI artifact in case we want to test the bundle before
merging changes into master.

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.circleci/config.yml

@@ -133,7 +133,7 @@ jobs:
           name: Create the bundle
           command: cd bundler && ./create-bundle
       - store_artifacts:
-          path: bundler/dist/files.txt
+          path: bundler/dist/
       - persist_to_workspace:
           root: ./bundler
           paths: